Hydraulic electromagnetic well fishing tool



May 6, 1952 A. E. BIVINGS ETAL HYDRAULIC ELECTROMAGNETIC WELL FISHING TOOL Filed April 14, 1947 2 SHEETS-SHEET l dk; Tm T l E; Il 38 I f4 7o '-42 f/ao '1% 46 s 72 20 :j lo l .5 Y E/zo 74- 3 i -l8 S 7655 4a l A I@ 38 :s 50

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May 6, 1952 A. E. BlvlNGs ETAL HYDRAULIC ELECTROMAGNETIC WELL FISHING TOOL Filed April 14. 1947 2 SHEETS-SHEET 2 Fig Inventors Albert E. Bivings v Pere H. Dunnam John A. Bvings @wm Attomqys I/ 3 6 M i m. Q, M, w m 4 Fw nlu\ @L /M u (IL A x l n A w t Patented May 6, 1952 HYDRAULIC LECTROMAGNETIC WELL .FISHING TOOL Albert E. Bivings, JohnA. Bivings, and Pete H. Dunnam, Odessa, Tex.

Application April 14, 1947, Serial No. 741,360

4 Claims. 1

This invention relates generally to well fishing tools, and more particularly to a well fishing tool assembly comprising'an electro-magnet secured to the lower end of an elongated casing with an hydraulic pump and an electric motor mounted within the casing, with cable means for lowering the casing into a well, the pump being adapted to flush material from beneath the casing, together with further novel means for removing the cable and electrical leads from the casing when the same becomes jammed.

A primary object of this invention is to provide a well fishing tool which can be quickly lowered. into a well, without the necessity of using a string of drill pipe, thus saving a great deal of time and t labor in the fishing operations.

Another object of this invention is to provide the well fishing tool with means whereby the Cable members and electrical leads ordinarily used with the tool may be removed from the casing lodged or jammed, such removal simultaneously providing for ideal conditions with a View to the subsequent attachment of a string of rods to the casing.

stm another object, 'ancillary' to 'the immedi ately preceding object, iszto provide valvemeans whereby normal ilushing by water forced downwardly through the said drill pipe ish directed through the casing and through the electro-magnet at the lower end of the casing, thus allowing a pump located at the surface of the ground to beused, Another object of this vinvention is to provide for the useof the clear Water drawn from a point spaced above the lodged article in the Well to be usedqfor flushing purposes. n t

Still another object of this invention is to provide for the equalization of interior and exterior pressures in the windings fofu'the electric motor for use at great depths. K y Y And a last object to be specifically mentioned is to provide adevice of this character which is relatively inexpensive and practicable to manufacture, simple and convenient to use, and which will give generally efficient and durable service. l Withthese objects definitely in View, this invention resides in certain novel features of construction, combination Yand arrangement ofvparts 20 when the same may -by inadvertence become and portions as will be described in detail hereinafter and particularly set forth in the appended claims, reference being had to the accompanying drawings which form a material part of this application, and in which:

Figure 1 is a fragmentary vertical sectional View of' a portion of a Well with this invention suspended therein and shown in elevation, the viewv including the representation of a lost object imbedded in sediment in the lower portion ofthe well;

Figure 2 is a similar view, showing the upper portion of the invention, enlarged and in vertical cross-section, the electric motor and pump being shown in elevation, this View being adapted to be read in connection With Figure 3;

Figure v3 is a similar view of the lower portion of this invention, also shown in Vertical cross-section;

Figure 4 is a horizontal sectional view, taken on the line 4 4 in Figure 3; and,

Figure 5 is a horizontal sectional view, taken on the line 5-5 in Figure 2.

Similar characters of reference designate similar or identical parts and portions throughout the specication andY throughout the several views of the drawings.

Referring now to the drawings in detail, it will be noted that the ground or rock I 0 and the well d the electro-magnet, thus adapting the device lining |20, the sediment I2 and the lost `metallic object I4 constitute important portions of the environment wherewith this invention is adapted to be used. In this connection it should be pointed out that in this specication the term casing has been retained for use with reference to the metallic container for the main elements of this invention, and that the `term should not be associated with the lining l2. The casing is constructed in six parts, each being generally tubular and threadedly secured to the other parts. Referring to these parts in order, the cap I6 is secured Vto the top end of the .short top section I 8 by a pair of shear pins 30. An upper intermediate section 22 is similarly secured by tapered screw l threads 24 and 26 to the upper section I8 and to a lower intermediate section 28. A lower section 30 is'secured by taper screw threads 32 and 34, to the lower intermediate section 23 and to the upper end of the section at the bottom end of thev casing, indicated at 36. i

It will be understood that this invention contemplates the use of a reel at the surface adapted to pay out and pay on the flexible cable 38, by which this casing is lowered and raised in the well lining I2, the lower end of the cable being provided with a suitable attachment member 40 whereby the cable is retained on the cap I6, the cap being apertured as at 42 to receive this attachment member and to receive an insulative plug 44, through which flexible electrical leads are inserted. These electrical leads are connectible, by means of the plug 46 to the electric cable 48 and to a similar cable preferably incorporated with the flexible cable 38, it being understood that the incorporation of this electrical cable with the suspension cable 38 is a matter of individual preferment and mechanical expediency and that a second reel may be provided at the surface to accommodate a flexible electrical cableseparately from the cable 38.

The cable 4B is connected to an electric motor 50, and leads 52 depend from this cable -to the electro-magnet 54 which is mounted in the lower end section 36 of the casing. Obviously, the electro-magnet 54 must be controllable separately from the electric motor 50, and this control is achieved by separate leads and separate switches at the lsurface and not illustrated in the accompanying drawings. In this connection, it isV contemplated to include a reasonably sensitive ammeter in the electro-magnet circuit with a view to determination by the operator of the device of the contact or non-contact of the electromagnet with a magnetizable object, as illustrated at I4. The theory of this determination relies of the fact that the reluctance of the magnetic circuit is suddenly and materially changed when the object I4 is brought into contact with the electro-magnet. A change in the reluctance of the magnetic circuit will cause a definite flicker,

as well as a small permanent change, in the current flowing through the electro-magnetic circuit, and this flicker and/or permanent change in current strength may be noted by the operator, if the ammeter be carefully watched.

If, during the use of this well fishing tool, and

during the operation of raising the retrieved object to the surface, this object should become disengaged from the electro-magnet, a sudden increase in the reluctance of the magnetic circuit will cause a similar flicker and change in the ammeter reading, and the operator will be warned of such disengagement. It should be noted that certain types of wiring in the electro-magnet will adapt the same for easier determination of such contact and non-contact of vthe member I4, the general principle of such wiring including the provision of bi-poles or multi-poles in the magnet, this bi-polar or multi-polar construction considerably increasing the variation in current at the time of engagement or disengagement of the object I4, which constitutes a strap or armature in the magnetic circuit.

The electric motor 56 is operatively connected with a hydraulic pump 56 which has an inlet 58 and an outlet tube 60 which will preferably be flexible in character and is connected at its lower end with a nipple 62, to the upper end of a channeled portion 64 of the lower end member 36 of the casing. A limited quantity of Water is drawn into the casing through the vents 66 in the lower section 30 of the casing, but the chief source of Water for the hydraulic pump is the relatively clear water at a height in the order -of 25 feet above the upper end of the casing. Water -is drawn from this portion of the well through the tube 68 which is secured by a nipple 'I0 to the cap I6, which cap and the upper section I8 of the casing are apertured as at 'I2 and '14, respectively, to allow water to flow downwardly into the interior of the casing.

The flap valves 16 and 78, closing the lower end of the channel 14 and the vents 66, respectively, will normally remain open. However, when the casing itself becomes lodged in the well, or when the object I4 cannot be dislodged without applying unduly heavy strain upon the cable 38, it is desirable to remove the cap I3, together with the cable 38 and the tube 68, and to sink a string of drill rods into the well for the purpose of retrieving the casing and/or the object I4. This exigency is provided for by inserting a plurality of soft iron shear pins into registering apertures provided therefor in the upper end section I8 and the cap I6, so that the cap may be easily removed from the upper end section I8 by applying sufficient torque on the cable 38. Simultaneously, the electrical leads at the upper end of the plug 46 will be severed, and the exposed threads 28 on the upper end section I8 will provide ideal means for securing the lower end of the string of drill pipe to the top end of the casing. The use of the llap valves 16 and I8 will now be clearly understood. With the string of drill pipe lowered into the well and secured to the upper end of the casing, the application of normal methods of providing flushing water to the lower end of the casing must now be used, and it will be seen that when water underl pressure is forced down through the drill pipe the flap valves 'I6 and i8 will close, creating a pressure within the casing. To open the channel 64 and to allow the water under pressure to escape to the lower end of the casing, a plurality of side channels 82 are provided, communicating this channel 64 with the interior of the casing, the upper ends of these channels 82 being closed by blow plugs 84 which rupture under the increased pressure within the casing and allow flow of the flushing water from the interior of the casing out through the channel 64.

This invention is adapted for use in wells of great depth and the pressure at such depth is suicient to cause the fouling of the windings of the electric motor 50 and the electro-magnet 54 unless provision is made to equalize the internal pressure of these units with the external pressure. This invention envisages the provision of means to thus equalize these pressures and this means includes a cylinder 86 closed at each end and connected by tubes r88 and 90 to a screened vent 92 and a T-member, respectively. The screened vent 92 communicates the interior of the cylinder 86 with the exterior of the casing, and the T-member A94 communicates the outer end of the cylinder, that is, the tube 90, with tubes 96 and 98 leading to the interior vportions and windings of the electric motor 58 and electro-magnet 5'4, respectively. It is preferred that the lower end member 36 of the casing be formed with a centrally upset portion |68, in the upper face of which the blow plugs 84 -are located and to the side of which longitudinally disposed channels are provided for the electrical leads 52 and to provide communication between the windings of the electro-magnet 54 and the tube 98, which latter tube is preferably secured by a nipple |62 in the upper end of the short channel leading to the electro-magnet windings.

rIhe cylinder-86 may be secured by set-screws |04 to the section 30 of the casing, and the electric motor 5I) may be similarly secured by spacing members |06 and set screws IDB, to the section 22 of the casing. It is preferred that the lower end section 36 of the casing be provided with exterior uting IIO, and the section 28 of the casing will be similarly provided with fluting II2, this uting providing for proper guidance of the casing within the well. lining |20 and simultaneously allowing movement of the sediment I2 upwardlyv around the casing under the influence of the flushing water. It will be understood, of course, that the flushing water is of service in removing this sediment in order that the casing may be gradually lowered into the well to con-- tact the member I4. The operation of this invention will be clearly understood from the foregoing description of the mechanical details thereof, taken in connection with the above recitation of the objects sought to be achieved by this invention but, in recapitulation, it may be added that the casing is lowered into the well by the flexible cable 38 which is wound on a power reel at the surface. The relatively long tube 68 will be suitably supported on the cable 38, a major portion of this tube being contemplated as constructed of rubber or other flexible material, the lowering being continued until the lower end 36 of the casing rests upon the sediment I2 ordinarily encountered in fishing operations. It will be clear that the vents 66 will allow the casing to fill with water in the well and that the flap valves 'I6 and 'I8 will normally remain open. As the depth of the casing increases the pressure at the screened vent 92 will increase and the plunger II4 will move, as upwardly in Figure 3, to force hydraulic fluid of the general nature of transformer oil, contained in the cylinder 86, into the windings of the electric motor 50 and electromagnet 54, thus equalizing the exterior and interior pressures. The casing will now be in a position represented in Figure 1, and the switch controlled at the surface will be manipulated to start the electric motor 50 and the hydraulic pump 56 will force water down from the tube 68 through the tube 60 and the channel 64 into the sediment I2. This action causes the sediment l2 to be displaced upwardly through the well casing I2, and continuation of this flushing action will allow the casing to settle until the electrof magnet 54 comes in contact with the object I4. The operator will be provided with a depth meter and a load meter whereby he can accurately gauge the position of the casing, and since the depth of the object I4 will be usually known with reasonable accuracy, it will be possible to energize the electro-magnet 54 at a time shortly before the object I4 is reached. A deflection of the above described ammeter connected in the electromagnet circuit will then indicate to the operator the exact time that the object I4 is encountered and proper contact made therewith. With the electro-magnet continuously energized, the hoisting operation is then begun and ordinarily continued until the object I4 is removed from the well. If, inadvertently, the object I4 becomes disengaged from the electro-magnet, a deflection of this same ammeter will indicate such disengagement and the fishing operation will necessarily have to be repeated. Finally, in the event that the casing and/or the object I4 becomes lodged so tightly in the well that its casing cannot be moved either up or down, the application of a predetermined strain on the cable 38 results in the shearing of the pins 80, and the cap I8, together with the tube 68 will be elevated-to the surface. A string of drill pipe may then be inserted in the well, the lower end thereof being secured to the threads 20 on the upper end portion I8 of the casing, whereafter normal shing operation may be continued. It will be obvious that considerable time may be saved by the use of this invention since the casing can be quickly lowered and the sinking of a long string of drill rods will ordinarily be unnecessary.

Many and various minor modifications may be made in the mechanical details of this invention, all without departure from the spirit and scope thereof and the foregoing description and the drawings are submitted as illustrative rather than as limiting. With this in mind, limitation of this invention is sought only in accordance with the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. A well fishing tool assembly comprising an electromagnet secured to the lower end of an elongated casing, an interconnected electric motor and hydraulic pump secured to said casing and having an outlet at the lower end of said magnet and an inlet tube extending above said casing, means for lowering the casing into a Well, and flexible electric leads for said motor and electro-magnet, comprising a cylinder having tubes connecting the cylinder to the exterior of said casing and to the space occupied by said windings, a fluid in one end of said cylinder and in the tube leading to the windings, and a plunger in said cylinder actuated by external pressure.

2. A well fishing tool assembly comprising an electromagnet secured to the lower end of an elongated casing, an interconnected electric motor and hydraulic pump secured to said casing and having an outlet at the lower end of said magnet and an inlet tube extending above said casing, means for lowering the casing into a well, and flexible electric leads for said motor and electro-magnet, and means to equalize the interior and exterior pressures on the windings of said electromagnet comprising a cylinder having tubes connecting the cylinder to the exterior of said casing and to the space occupied by said windings, transformer oil in one end of said cylinder and in the tube leading to the windings, and a plunger in said cylinder actuated by external pressure.

3. A well fishing tool assembly comprising an electromagnet secured to the lower end of an elongated casing, an interconnected electric motor and hydraulic pump secured to and closing the lower end of said casing and having an outlet at the lower end of said magnet, a cap separably secured to and closing the top of the casing, an inlet tube carried by said cap and extending above said casing, whereby relatively clean water is fed to said pump during operation, said casing having a centrally apertured threaded portion at the top exposed when said cap is separated from the casing allowing securement of drill pipe to the casing in an emergency, a channel through the top of said casing communicating with said inlet tube, a flap valve to close said channel when pressure is increased within the casing, a branching side channel communicating with said outlet tube and the interior of the casing, and a pressure blow plug closing this last mentioned channel.

4. A well fishing tool assembly according to J OHNIA.',BIVINGS. .PETEHVDUNNAM.

REFERENCES sCmEi 

